Non-linear components such as diodes, thyristors, current/voltage source converters, switched mode power supplies, and motor drives are widely used in power systems. They can generate harmonics and reactive power which greatly degrades power quality. In addition, the presence of large unbalanced industrial loads such as single phase traction systems, electrical furnaces and welding machines can produce significant current and voltage distortions in the power systems. There are several deleterious effects of high distortion in the current or voltage waveforms and poor power factor. These conditions can increase power loss, cause vibrations and noise in motors, result in malfunction and failure of sensitive equipment, etc. Harmonic currents may also cause resonance between shunt capacitance and series inductance of the distribution and transmission lines. For at least these reasons, standards such as IEEE-519 have placed several limits on both consumers and utilities.